1. Field of the Invention
The present invention relates to a protective tube and a protective tube attaching method.
2. Description of the Related Art
A wire harness to be arranged on a vehicle such as a car has a configuration as follows. That is, in an electric wire bundle (trunk line) in which a plurality of electric wires are bundled, predetermined electric wires (branch lines) are split or connectors are connected to terminal ends of the trunk line or the branch lines. In addition, such a wire harness may be covered with a protective tube made of a flexible resin in order to protect the electric wires. The protective tube is roughly classified into a circular insertion protective tube having a closed sectional shape perpendicular to its tube axis, and a C-shaped protective tube having a slit and hence having an opened sectional shape perpendicular to its tube axis.
For example, the electric wires including terminals crimped at their terminal ends are inserted into the insertion protective tube in advance. The electric wires are exposed from the insertion protective tube in the vicinity of each connector connection portion (underhead part of each connector). In this manner, it is necessary to secure a work margin (margin length for bending the electric wires and inserting the terminals into the connector) when the terminals attached to the terminal ends of the electric wires are inserted into the connector. For this reason, a worker cannot outer-fit the protective tube to the wire harness extremely enough to allow the protective tube to abut against connectors etc. on the opposite end sides of the wire harness. On the other hand, the protective tube with the slit can be outer-fitted through the slit after connector connection work. Thus, the protective tube with the slit can be made to abut against connectors etc. on the opposite end sides of the wire harness. However, an adhesive tape etc. has to be wound on the outer circumference of the protective tube with the slit to thereby restrict the opening thereof. Therefore, extra work or an extra member is required to thereby increase the cost.
Therefore, a protective tube attaching structure of a wire harness disclosed in JP-A-11-37349 or a wire protecting device for use in an automatic transmission and a wire protecting device attaching method disclosed in JP-A-2003-65426 have been known as a solution to such a problem.
The protective tube attaching structure of the wire harness disclosed in JP-A-11-37349 has the following configuration. That is, as shown in FIGS. 8A to 8C, a tape 505 is wound around an electric wire group of a divergence point 503 in a plurality of branch lines 501 to be firmly fixed to the electric wire group. In addition, a common supply tube 507 made of a flexible resin is provided to be outer-fitted to the electric wires 501, and the inner circumferential surface of the common supply tube 507 is made to abut against the tape 505 so that the common supply tube 507 can be moved beyond the tape 505 but retained at a stop position. As shown in FIG. 8A, a slit-including corrugated tube 511 is put on a trunk line 509, and set to be attached to a position where the tape 505 can be exposed from a front end of the corrugated tube 511. When connectors 513 at respective branch line terminal ends are connected to a partner component 515, the common supply tube 507 is retained at a position on the trunk line side, as shown in FIG. 8B. After the connectors are connected, the common supply tube 507 is moved and retained to be outer-fitted to the electric wires 501, as shown in FIG. 8C.
In addition, according to the wire protecting device for use in the automatic transmission and the wire detecting device attaching method disclosed in JP-A-2003-65426, a protective tube 519 of a wire harness sub-assembly 517 includes a small-diameter protective tube (small diameter protective tube) 521, and a large-diameter protective tube (large diameter protective tube) 523 which is put on the small-diameter protective tube 521 so as to be movable relatively thereto, as shown in FIG. 9A. The small-diameter protective tube 521 is biased toward a connector 513 and the large-diameter protective tube 523 is biased toward a sensor 525. In this state, the small-diameter protective tube 521 is fixed to a predetermined position of an A/T case 529 by a harness clamp 527. In this state, the harness clamp 527 prevents the large-diameter protective tube 523 from moving toward the connector 513, so as to restrict the position of the large-diameter protective tube 523, as shown in FIG. 9B. Due to the restriction on the position of the large-diameter protective tube 523, a wire exposure portion 531 can be covered with the large-diameter protective tube 523 so as to be protected thereby.
However, in the case of the protective tube attaching structure of the wire harness according to JP-A-11-37349, it is necessary to wind the tube retaining tape 505 to thereby fix the tube retaining tape 505 to the electric wire group firmly. Thus, workability is poor. In addition, in the case of the wire protecting device for use in the automatic transmission and the wire protecting device attaching method disclosed in JP-A-2003-65426, the harness clamp 527 for restricting the position of the large-diameter protective tube 523 is required and the two tubes have to be pressed by hands to do work during attachment. Thus, workability is poor.